From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boaz Harrosh Subject: Re: [PATCH 1/8] exofs: Kbuild, Headers and osd utils Date: Mon, 16 Feb 2009 12:29:06 +0200 Message-ID: <49993FF2.9050200@panasas.com> References: <499928A3.60507@panasas.com> <20090216180028C.fujita.tomonori@lab.ntt.co.jp> <49992F99.1060404@panasas.com> <20090216183750H.fujita.tomonori@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: avishay@gmail.com, jeff@garzik.org, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, osd-dev@open-osd.org, linux-kernel@vger.kernel.org, James.Bottomley@HansenPartnership.com, jens.axboe@oracle.com, linux-scsi@vger.kernel.org To: FUJITA Tomonori Return-path: In-Reply-To: <20090216183750H.fujita.tomonori@lab.ntt.co.jp> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org FUJITA Tomonori wrote: > On Mon, 16 Feb 2009 11:19:21 +0200 > Boaz Harrosh wrote: > >>>> Also looking >>>> ahead I will have RAID 0, 1, 5, and 6 on objects of different devices. bio >>>> is the perfect collector for memory information in this situation. >>> You will add such features to exofs, handling multiple devices >>> internally? >>> >> Multiple objects on Multiple devices, Yes. > > I thought that exofs is kinda example (reference) file system. > > Nobody has seen your code. Let's discuss when we have the > code. Over-designing for what we've not seen is not a good idea. > Thanks for the insults, and high credit ;) Yes it's "kinda example (reference) file system" of a pNFS-objects file system. What can I do life is tough. > >>>> exofs is not the first and only file system who is using bios. Proof of >>>> the matter is that block exports a bio submit routine. >>> Seems that exofs just passes pages and the ULD sends a SCSI command >>> including these pages. I don't see how exofs needs to handle bio >>> directly. >>> >> How do you propose to collect these pages? and keep them without allocating >> an extra list? without pre-allocating a struct request? and without re-inventing >> the bio structure? > > I don't think that allocating an extra list (or something) to keep > them hurts performance. We can talk about it when you have the real > performance results. So you are the one that starts to invent the wheel here. I thought I was the one that does that, only you only called me by names, because you never showed me where. But please only answer one question for me: Please don't write back if you do not answer this question: Why do other filesystems allow to use bios? are they going to stop? Who is going to remove that? And as I said, I am going to remove it for now, please be patient. You have never herd from me that I refuse to do it, did you? Boaz